As an alternative battery powered Mini PC capable of running Linux I'm now using a WD My Passport Wireless mobile storage device running Debian with LXDE.
The device comes with a "500GB" HDD which is partitioned with a visible 496GB HPFS/NTFS/exFAT file system and a hidden 4.3GB file system which I assume is used for recovery / factory resets. It also supports an SD card. The actual configured OS is a Buildroot Linux (version 3.2) installed on a UBIFS on eMMC along with the bootloader etc.
But the exciting part is the 2x2 MIMO Wi-Fi Module meaning both wifi network connectivity together with a wifi access point. And as the CPU shows as a ' am335xevm' or AM335x Evaluation Module which is a Sitara AM335x ARM Cortex-A8 CPU one can run Linux from 'chroot' environment using a previously created ARM root file system.
Because the installed OS doesn't support the 'ext4' file system I initially took one of my ARM RFS images and rebuilt it on 'ext3'. I could then run this directly as a mounted image or by copying it to the (effectively unused) hidden partition. I can also run a 'chroot' environment by copying the RFS to an SD card partition. Also as the CPU / memory configuration is very similar to the Beaglebone Black I can also use the various images provided for that board.
Here's a video of accessing the WD My Passport Wireless from a Windows PC (MINIX Neo Z64W) and running a Debian 'chroot' ... see https://youtu.be/1noXmiHLqt4
... I've also added pictures showing accessing the device from an Android Nexus 4 phone and running various Linux flavours (Debian, Ubuntu, Xubuntu) or running Linux from the command line together with a picture showing access from a Nexus 5 and using the internet via a web browser on Debian.
Although running Linux with a GUI on a phone might only be suitable for a party trick, I've found using the CLI very useful in writing code and shell scripts whilst on the move.